oracle linux dnf update "certificate cannot be authenticated" error

if you are getting errors from oracle linux dnf update such as

# dnf update

Oracle Linux 8 BaseOS Latest (x86_64)                                                               

0.0  B/s |   0  B     00:00

Errors during downloading metadata for repository 'ol8_baseos_latest':
  - Curl error (60): 
Peer certificate cannot be authenticated with given CA certificates for https://yum.oracle.com/repo/OracleLinux/OL8/baseos/latest/x86_64/repodata/repomd.xml 
[SSL certificate problem: unable to get local issuer certificate]

Error: Failed to download metadata for repo 'ol8_baseos_latest': 
Cannot download repomd.xml: 
Cannot download repodata/repomd.xml: All mirrors were tried

maybe its because you are using ZSCALER and so you can try DISABLING SSL checks by adding sslverify=0 to your dnf.conf

$ cat /etc/dnf/dnf.conf
[main]
gpgcheck=1
installonly_limit=3
clean_requirements_on_remove=True
best=True
skip_if_unavailable=False
sslverify=0

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